1. Field of the Invention
This disclosure relates to data buffers and, in particular, to a system and method for controlling a data buffer for transmitting compressed data.
2. Description of the Related Art
In server applications it is desirable to convert input data to bit sequences insertable in a bit stream for transmission. For example, in the Motion Picture Experts Group Standard (MPEG), input video data is encoded as compressed bitstreams as specified in the MPEG standard specification; i.e. MPEG TEST MODEL 4, "Coded Representation of Picture and Audio Information", ISO-IEC/JTC1/SC29/EG11, CCITT SG XV, Working Party XV/1, Document AVC-445b, February 1993. It is advantageous to store the compressed input data in short independently decodable bit sequences representing clips such as video clips, where a clip is defined to be a sequence of video frames. It is preferable to have such clips encoded and stored for later transmission in an arbitrary order.
Such decoding from concatenated bit sequences allows for seamless switching to be performed between different bitstreams at certain access points. It is preferred that switching be performed without gaps or loss of data at the switching points and without buffer underflow overflow at times after performing the switching. These features would be applicable for inserting advertisement clips into MPEG bitstreams, as well as jumping from one access point to another in the same bitstream or looping on a particular clip.